Dear Experts,
I am facing a serious issue and need your help to resolve this. I am providing internet services in a small city (WISP) having 200 users. I have CIR internet service with Public IP's (Limited 16). When I assign an Public IP to Mikrotik WAN for internet access to Mikrotik, it's working fine for some day on user end and sometime only 2, 3 days. But after that my Public IP got blacklisted on many websites including Google and client need to do Human Verification(I'm not a Robot) to access that site (Like Google.com , Websites on Cloudflare etc). When I change this IP, problem solved for some day then again this issue happened. I think I have missed any firewall rule, so I am attaching my firewall screen shots.
Please help me to resolve this issue..

Check if your IP's listed in spam databases, for example here
https://2ip.ru/spam/

Check if the firewall is sufficient to not be an open relay or dns resolver.

The first step is to upgrade your firmware.

1) update RouterOS
2) your firewall is open and wrong on input chain
3) rework your firewall in style: accept only needed, drop all else

Or do "/ip firewall export" or better "/export hide-sensitive" and post here for advises (screenshot is not sufficient)